Specifications

FDDI RING TOPOLOGY
5-2
DUAL RING WITH TREES
A Dual Ring with Trees configuration uses dual attachment concentrators, single
attachment concentrators, and single attachment stations to form tree structures.
Single attachment stations and single attachment concentrators connect to the
dual attachment concentrator M ports instead of the ring. This configuration
enhances network reliability because dual attachment concentrators
automatically reconfigure the network each time stations are inserted or removed
from the ring.
Another advantage of the Dual Ring with Trees configuration is cost. Adapter
boards for single attachment stations are cheaper than adapter boards for dual
attachment concentrators. Figure 5-2 shows a typical Dual Ring with Trees
configuration.
Figure 5-2. FDDI Dual Ring of Trees
FDDI DUAL
COUNTER-ROTATING RING
NETWORK
DUAL ATTACHED
CONCENTRATOR
DUAL ATTACHED
CONCENTRATOR
SINGLE ATTACHED
CONCENTRATOR
PRIMARY RING
SECONDARY RING
SINGLE ATTACHED
STATIONS
SINGLE ATTACHED
STATIONS
TREE STRUCTURE